| /* |
| * Seiko Instruments S-35390A RTC Driver |
| * |
| * Copyright (c) 2007 Byron Bradley |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/rtc.h> |
| #include <linux/i2c.h> |
| #include <linux/bitrev.h> |
| #include <linux/bcd.h> |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| |
| #define S35390A_CMD_STATUS1 0 |
| #define S35390A_CMD_STATUS2 1 |
| #define S35390A_CMD_TIME1 2 |
| #define S35390A_CMD_TIME2 3 |
| #define S35390A_CMD_INT2_REG1 5 |
| |
| #define S35390A_BYTE_YEAR 0 |
| #define S35390A_BYTE_MONTH 1 |
| #define S35390A_BYTE_DAY 2 |
| #define S35390A_BYTE_WDAY 3 |
| #define S35390A_BYTE_HOURS 4 |
| #define S35390A_BYTE_MINS 5 |
| #define S35390A_BYTE_SECS 6 |
| |
| #define S35390A_ALRM_BYTE_WDAY 0 |
| #define S35390A_ALRM_BYTE_HOURS 1 |
| #define S35390A_ALRM_BYTE_MINS 2 |
| |
| /* flags for STATUS1 */ |
| #define S35390A_FLAG_POC 0x01 |
| #define S35390A_FLAG_BLD 0x02 |
| #define S35390A_FLAG_INT2 0x04 |
| #define S35390A_FLAG_24H 0x40 |
| #define S35390A_FLAG_RESET 0x80 |
| |
| /* flag for STATUS2 */ |
| #define S35390A_FLAG_TEST 0x01 |
| |
| #define S35390A_INT2_MODE_MASK 0xF0 |
| |
| #define S35390A_INT2_MODE_NOINTR 0x00 |
| #define S35390A_INT2_MODE_FREQ 0x10 |
| #define S35390A_INT2_MODE_ALARM 0x40 |
| #define S35390A_INT2_MODE_PMIN_EDG 0x20 |
| |
| static const struct i2c_device_id s35390a_id[] = { |
| { "s35390a", 0 }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(i2c, s35390a_id); |
| |
| static const struct of_device_id s35390a_of_match[] = { |
| { .compatible = "s35390a" }, |
| { .compatible = "sii,s35390a" }, |
| { } |
| }; |
| MODULE_DEVICE_TABLE(of, s35390a_of_match); |
| |
| struct s35390a { |
| struct i2c_client *client[8]; |
| struct rtc_device *rtc; |
| int twentyfourhour; |
| }; |
| |
| static int s35390a_set_reg(struct s35390a *s35390a, int reg, char *buf, int len) |
| { |
| struct i2c_client *client = s35390a->client[reg]; |
| struct i2c_msg msg[] = { |
| { |
| .addr = client->addr, |
| .len = len, |
| .buf = buf |
| }, |
| }; |
| |
| if ((i2c_transfer(client->adapter, msg, 1)) != 1) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| static int s35390a_get_reg(struct s35390a *s35390a, int reg, char *buf, int len) |
| { |
| struct i2c_client *client = s35390a->client[reg]; |
| struct i2c_msg msg[] = { |
| { |
| .addr = client->addr, |
| .flags = I2C_M_RD, |
| .len = len, |
| .buf = buf |
| }, |
| }; |
| |
| if ((i2c_transfer(client->adapter, msg, 1)) != 1) |
| return -EIO; |
| |
| return 0; |
| } |
| |
| /* |
| * Returns <0 on error, 0 if rtc is setup fine and 1 if the chip was reset. |
| * To keep the information if an irq is pending, pass the value read from |
| * STATUS1 to the caller. |
| */ |
| static int s35390a_reset(struct s35390a *s35390a, char *status1) |
| { |
| char buf; |
| int ret; |
| unsigned initcount = 0; |
| |
| ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, status1, 1); |
| if (ret < 0) |
| return ret; |
| |
| if (*status1 & S35390A_FLAG_POC) |
| /* |
| * Do not communicate for 0.5 seconds since the power-on |
| * detection circuit is in operation. |
| */ |
| msleep(500); |
| else if (!(*status1 & S35390A_FLAG_BLD)) |
| /* |
| * If both POC and BLD are unset everything is fine. |
| */ |
| return 0; |
| |
| /* |
| * At least one of POC and BLD are set, so reinitialise chip. Keeping |
| * this information in the hardware to know later that the time isn't |
| * valid is unfortunately not possible because POC and BLD are cleared |
| * on read. So the reset is best done now. |
| * |
| * The 24H bit is kept over reset, so set it already here. |
| */ |
| initialize: |
| *status1 = S35390A_FLAG_24H; |
| buf = S35390A_FLAG_RESET | S35390A_FLAG_24H; |
| ret = s35390a_set_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1); |
| |
| if (ret < 0) |
| return ret; |
| |
| ret = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &buf, 1); |
| if (ret < 0) |
| return ret; |
| |
| if (buf & (S35390A_FLAG_POC | S35390A_FLAG_BLD)) { |
| /* Try up to five times to reset the chip */ |
| if (initcount < 5) { |
| ++initcount; |
| goto initialize; |
| } else |
| return -EIO; |
| } |
| |
| return 1; |
| } |
| |
| static int s35390a_disable_test_mode(struct s35390a *s35390a) |
| { |
| char buf[1]; |
| |
| if (s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)) < 0) |
| return -EIO; |
| |
| if (!(buf[0] & S35390A_FLAG_TEST)) |
| return 0; |
| |
| buf[0] &= ~S35390A_FLAG_TEST; |
| return s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, buf, sizeof(buf)); |
| } |
| |
| static char s35390a_hr2reg(struct s35390a *s35390a, int hour) |
| { |
| if (s35390a->twentyfourhour) |
| return bin2bcd(hour); |
| |
| if (hour < 12) |
| return bin2bcd(hour); |
| |
| return 0x40 | bin2bcd(hour - 12); |
| } |
| |
| static int s35390a_reg2hr(struct s35390a *s35390a, char reg) |
| { |
| unsigned hour; |
| |
| if (s35390a->twentyfourhour) |
| return bcd2bin(reg & 0x3f); |
| |
| hour = bcd2bin(reg & 0x3f); |
| if (reg & 0x40) |
| hour += 12; |
| |
| return hour; |
| } |
| |
| static int s35390a_set_datetime(struct i2c_client *client, struct rtc_time *tm) |
| { |
| struct s35390a *s35390a = i2c_get_clientdata(client); |
| int i, err; |
| char buf[7]; |
| |
| dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d mday=%d, " |
| "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, |
| tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, |
| tm->tm_wday); |
| |
| buf[S35390A_BYTE_YEAR] = bin2bcd(tm->tm_year - 100); |
| buf[S35390A_BYTE_MONTH] = bin2bcd(tm->tm_mon + 1); |
| buf[S35390A_BYTE_DAY] = bin2bcd(tm->tm_mday); |
| buf[S35390A_BYTE_WDAY] = bin2bcd(tm->tm_wday); |
| buf[S35390A_BYTE_HOURS] = s35390a_hr2reg(s35390a, tm->tm_hour); |
| buf[S35390A_BYTE_MINS] = bin2bcd(tm->tm_min); |
| buf[S35390A_BYTE_SECS] = bin2bcd(tm->tm_sec); |
| |
| /* This chip expects the bits of each byte to be in reverse order */ |
| for (i = 0; i < 7; ++i) |
| buf[i] = bitrev8(buf[i]); |
| |
| err = s35390a_set_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); |
| |
| return err; |
| } |
| |
| static int s35390a_get_datetime(struct i2c_client *client, struct rtc_time *tm) |
| { |
| struct s35390a *s35390a = i2c_get_clientdata(client); |
| char buf[7]; |
| int i, err; |
| |
| err = s35390a_get_reg(s35390a, S35390A_CMD_TIME1, buf, sizeof(buf)); |
| if (err < 0) |
| return err; |
| |
| /* This chip returns the bits of each byte in reverse order */ |
| for (i = 0; i < 7; ++i) |
| buf[i] = bitrev8(buf[i]); |
| |
| tm->tm_sec = bcd2bin(buf[S35390A_BYTE_SECS]); |
| tm->tm_min = bcd2bin(buf[S35390A_BYTE_MINS]); |
| tm->tm_hour = s35390a_reg2hr(s35390a, buf[S35390A_BYTE_HOURS]); |
| tm->tm_wday = bcd2bin(buf[S35390A_BYTE_WDAY]); |
| tm->tm_mday = bcd2bin(buf[S35390A_BYTE_DAY]); |
| tm->tm_mon = bcd2bin(buf[S35390A_BYTE_MONTH]) - 1; |
| tm->tm_year = bcd2bin(buf[S35390A_BYTE_YEAR]) + 100; |
| |
| dev_dbg(&client->dev, "%s: tm is secs=%d, mins=%d, hours=%d, mday=%d, " |
| "mon=%d, year=%d, wday=%d\n", __func__, tm->tm_sec, |
| tm->tm_min, tm->tm_hour, tm->tm_mday, tm->tm_mon, tm->tm_year, |
| tm->tm_wday); |
| |
| return rtc_valid_tm(tm); |
| } |
| |
| static int s35390a_set_alarm(struct i2c_client *client, struct rtc_wkalrm *alm) |
| { |
| struct s35390a *s35390a = i2c_get_clientdata(client); |
| char buf[3], sts = 0; |
| int err, i; |
| |
| dev_dbg(&client->dev, "%s: alm is secs=%d, mins=%d, hours=%d mday=%d, "\ |
| "mon=%d, year=%d, wday=%d\n", __func__, alm->time.tm_sec, |
| alm->time.tm_min, alm->time.tm_hour, alm->time.tm_mday, |
| alm->time.tm_mon, alm->time.tm_year, alm->time.tm_wday); |
| |
| /* disable interrupt (which deasserts the irq line) */ |
| err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); |
| if (err < 0) |
| return err; |
| |
| /* clear pending interrupt (in STATUS1 only), if any */ |
| err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS1, &sts, sizeof(sts)); |
| if (err < 0) |
| return err; |
| |
| if (alm->enabled) |
| sts = S35390A_INT2_MODE_ALARM; |
| else |
| sts = S35390A_INT2_MODE_NOINTR; |
| |
| /* This chip expects the bits of each byte to be in reverse order */ |
| sts = bitrev8(sts); |
| |
| /* set interupt mode*/ |
| err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); |
| if (err < 0) |
| return err; |
| |
| if (alm->time.tm_wday != -1) |
| buf[S35390A_ALRM_BYTE_WDAY] = bin2bcd(alm->time.tm_wday) | 0x80; |
| else |
| buf[S35390A_ALRM_BYTE_WDAY] = 0; |
| |
| buf[S35390A_ALRM_BYTE_HOURS] = s35390a_hr2reg(s35390a, |
| alm->time.tm_hour) | 0x80; |
| buf[S35390A_ALRM_BYTE_MINS] = bin2bcd(alm->time.tm_min) | 0x80; |
| |
| if (alm->time.tm_hour >= 12) |
| buf[S35390A_ALRM_BYTE_HOURS] |= 0x40; |
| |
| for (i = 0; i < 3; ++i) |
| buf[i] = bitrev8(buf[i]); |
| |
| err = s35390a_set_reg(s35390a, S35390A_CMD_INT2_REG1, buf, |
| sizeof(buf)); |
| |
| return err; |
| } |
| |
| static int s35390a_read_alarm(struct i2c_client *client, struct rtc_wkalrm *alm) |
| { |
| struct s35390a *s35390a = i2c_get_clientdata(client); |
| char buf[3], sts; |
| int i, err; |
| |
| err = s35390a_get_reg(s35390a, S35390A_CMD_STATUS2, &sts, sizeof(sts)); |
| if (err < 0) |
| return err; |
| |
| if ((bitrev8(sts) & S35390A_INT2_MODE_MASK) != S35390A_INT2_MODE_ALARM) { |
| /* |
| * When the alarm isn't enabled, the register to configure |
| * the alarm time isn't accessible. |
| */ |
| alm->enabled = 0; |
| return 0; |
| } else { |
| alm->enabled = 1; |
| } |
| |
| err = s35390a_get_reg(s35390a, S35390A_CMD_INT2_REG1, buf, sizeof(buf)); |
| if (err < 0) |
| return err; |
| |
| /* This chip returns the bits of each byte in reverse order */ |
| for (i = 0; i < 3; ++i) |
| buf[i] = bitrev8(buf[i]); |
| |
| /* |
| * B0 of the three matching registers is an enable flag. Iff it is set |
| * the configured value is used for matching. |
| */ |
| if (buf[S35390A_ALRM_BYTE_WDAY] & 0x80) |
| alm->time.tm_wday = |
| bcd2bin(buf[S35390A_ALRM_BYTE_WDAY] & ~0x80); |
| |
| if (buf[S35390A_ALRM_BYTE_HOURS] & 0x80) |
| alm->time.tm_hour = |
| s35390a_reg2hr(s35390a, |
| buf[S35390A_ALRM_BYTE_HOURS] & ~0x80); |
| |
| if (buf[S35390A_ALRM_BYTE_MINS] & 0x80) |
| alm->time.tm_min = bcd2bin(buf[S35390A_ALRM_BYTE_MINS] & ~0x80); |
| |
| /* alarm triggers always at s=0 */ |
| alm->time.tm_sec = 0; |
| |
| dev_dbg(&client->dev, "%s: alm is mins=%d, hours=%d, wday=%d\n", |
| __func__, alm->time.tm_min, alm->time.tm_hour, |
| alm->time.tm_wday); |
| |
| return 0; |
| } |
| |
| static int s35390a_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| { |
| return s35390a_read_alarm(to_i2c_client(dev), alm); |
| } |
| |
| static int s35390a_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm) |
| { |
| return s35390a_set_alarm(to_i2c_client(dev), alm); |
| } |
| |
| static int s35390a_rtc_read_time(struct device *dev, struct rtc_time *tm) |
| { |
| return s35390a_get_datetime(to_i2c_client(dev), tm); |
| } |
| |
| static int s35390a_rtc_set_time(struct device *dev, struct rtc_time *tm) |
| { |
| return s35390a_set_datetime(to_i2c_client(dev), tm); |
| } |
| |
| static const struct rtc_class_ops s35390a_rtc_ops = { |
| .read_time = s35390a_rtc_read_time, |
| .set_time = s35390a_rtc_set_time, |
| .set_alarm = s35390a_rtc_set_alarm, |
| .read_alarm = s35390a_rtc_read_alarm, |
| |
| }; |
| |
| static struct i2c_driver s35390a_driver; |
| |
| static int s35390a_probe(struct i2c_client *client, |
| const struct i2c_device_id *id) |
| { |
| int err, err_reset; |
| unsigned int i; |
| struct s35390a *s35390a; |
| struct rtc_time tm; |
| char buf, status1; |
| |
| if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { |
| err = -ENODEV; |
| goto exit; |
| } |
| |
| s35390a = devm_kzalloc(&client->dev, sizeof(struct s35390a), |
| GFP_KERNEL); |
| if (!s35390a) { |
| err = -ENOMEM; |
| goto exit; |
| } |
| |
| s35390a->client[0] = client; |
| i2c_set_clientdata(client, s35390a); |
| |
| /* This chip uses multiple addresses, use dummy devices for them */ |
| for (i = 1; i < 8; ++i) { |
| s35390a->client[i] = i2c_new_dummy(client->adapter, |
| client->addr + i); |
| if (!s35390a->client[i]) { |
| dev_err(&client->dev, "Address %02x unavailable\n", |
| client->addr + i); |
| err = -EBUSY; |
| goto exit_dummy; |
| } |
| } |
| |
| err_reset = s35390a_reset(s35390a, &status1); |
| if (err_reset < 0) { |
| err = err_reset; |
| dev_err(&client->dev, "error resetting chip\n"); |
| goto exit_dummy; |
| } |
| |
| if (status1 & S35390A_FLAG_24H) |
| s35390a->twentyfourhour = 1; |
| else |
| s35390a->twentyfourhour = 0; |
| |
| if (status1 & S35390A_FLAG_INT2) { |
| /* disable alarm (and maybe test mode) */ |
| buf = 0; |
| err = s35390a_set_reg(s35390a, S35390A_CMD_STATUS2, &buf, 1); |
| if (err < 0) { |
| dev_err(&client->dev, "error disabling alarm"); |
| goto exit_dummy; |
| } |
| } else { |
| err = s35390a_disable_test_mode(s35390a); |
| if (err < 0) { |
| dev_err(&client->dev, "error disabling test mode\n"); |
| goto exit_dummy; |
| } |
| } |
| |
| if (err_reset > 0 || s35390a_get_datetime(client, &tm) < 0) |
| dev_warn(&client->dev, "clock needs to be set\n"); |
| |
| device_set_wakeup_capable(&client->dev, 1); |
| |
| s35390a->rtc = devm_rtc_device_register(&client->dev, |
| s35390a_driver.driver.name, |
| &s35390a_rtc_ops, THIS_MODULE); |
| |
| if (IS_ERR(s35390a->rtc)) { |
| err = PTR_ERR(s35390a->rtc); |
| goto exit_dummy; |
| } |
| |
| if (status1 & S35390A_FLAG_INT2) |
| rtc_update_irq(s35390a->rtc, 1, RTC_AF); |
| |
| return 0; |
| |
| exit_dummy: |
| for (i = 1; i < 8; ++i) |
| if (s35390a->client[i]) |
| i2c_unregister_device(s35390a->client[i]); |
| |
| exit: |
| return err; |
| } |
| |
| static int s35390a_remove(struct i2c_client *client) |
| { |
| unsigned int i; |
| struct s35390a *s35390a = i2c_get_clientdata(client); |
| |
| for (i = 1; i < 8; ++i) |
| if (s35390a->client[i]) |
| i2c_unregister_device(s35390a->client[i]); |
| |
| return 0; |
| } |
| |
| static struct i2c_driver s35390a_driver = { |
| .driver = { |
| .name = "rtc-s35390a", |
| .of_match_table = of_match_ptr(s35390a_of_match), |
| }, |
| .probe = s35390a_probe, |
| .remove = s35390a_remove, |
| .id_table = s35390a_id, |
| }; |
| |
| module_i2c_driver(s35390a_driver); |
| |
| MODULE_AUTHOR("Byron Bradley <byron.bbradley@gmail.com>"); |
| MODULE_DESCRIPTION("S35390A RTC driver"); |
| MODULE_LICENSE("GPL"); |